CN112832884A

CN112832884A - Tensioner and engine

Info

Publication number: CN112832884A
Application number: CN201911165284.9A
Authority: CN
Inventors: 戚俊维; 张莹; 吴丰凯; 肖航; 甄洪梅; 鲍帅华; 赵乃博; 刘雪梅; 张元东
Original assignee: Zhejiang Geely Holding Group Co Ltd; Hunan Luoyou Engine Parts Co Ltd
Current assignee: Zhejiang Geely Holding Group Co Ltd; Hunan Luoyou Engine Parts Co Ltd
Priority date: 2019-11-25
Filing date: 2019-11-25
Publication date: 2021-05-25
Anticipated expiration: 2039-11-25
Also published as: CN112832884B

Abstract

The invention relates to a tensioner and an engine, which comprise a shell, an oil supply mechanism, a resetting piece and a plunger, wherein the oil supply mechanism, the resetting piece and the plunger are arranged in the shell; the oil supply mechanism comprises a rack, a gear, an inner rotor and an outer rotor, wherein the rack is meshed with the gear, the rack is used for driving the gear to rotate, the gear is fixedly connected with the inner rotor, the inner rotor is meshed with the outer rotor, and the inner rotor is used for driving the outer rotor to rotate; the reset piece is arranged in the plunger, the reset piece is used for pushing the plunger to reciprocate, the plunger is fixedly connected with the rack, and the plunger is used for driving the rack to move up and down; the invention can change the oil supply mode of the tensioner, avoid the chain from being stressed to be enlarged due to the change of the oil pressure, cause serious abrasion of a chain system, prolong the service life and also avoid the failure of the tensioner due to the fact that a high-pressure oil cavity of the tensioner cannot be established.

Description

Tensioner and engine

Technical Field

The invention relates to the technical field of tensioners, in particular to a tensioner and an engine.

Background

In the current market, timing chain transmission, timing gear transmission and timing belt transmission are mostly adopted in automobile timing transmission, and along with the continuous improvement of the power and the torque of an engine and the continuous improvement of timing chain technology and production precision, more engines adopt a timing chain system to replace a timing gear or a timing belt, and meanwhile, compared with the belt and gear transmission, the timing chain has the advantages of being free of maintenance, high in reliability, as long as the service life of a vehicle is prolonged, and the like.

In order to inhibit the vibration of the chain and ensure the stress of the timing system, the most common and best effect is the hydraulic automatic tensioner, the tensioner of the mechanism not only can compensate the chain due to the system installation error in the assembling process and the chain elongation after long-time abrasion, but also can absorb the vibration from the chain under the combined action of the plunger and the return spring because of the viscous damping generated between the fit clearance between the plunger and the shell and the hydraulic oil, thereby prolonging the service life of the timing chain system, reducing the vibration of the chain transmission system and improving the NVH effect.

At present, a main stream engine in the market is generally a check valve and pawl check mechanism, the pressure of engine oil from an engine oil pump overcomes the acting force of a check valve spring to open the check valve, and the engine oil enters a high-pressure oil cavity in the tensioner through an oil supply hole to form damping, so that the swinging and vibration of a chain are absorbed, and the transmission noise of the timing chain is reduced. The excessive engine oil is discharged to the outside of the tensioner through a fit clearance between the plunger and the shell or an oil drain groove on the plunger, and the overpressure protection effect is achieved.

Pawl non return mechanism guarantees the tensioning ware at the engine action in-process, the displacement of plunger remains at fairly the level throughout, can not be because of tensioning ware plunger in the return push-back in-process, the swing of chain is restricted to the oil pressure of its low-pressure chamber with reset spring's not enough spring force to cause the repeated contact-break away from of guide rail and tight chain ware, cause the unusual contact atress of chain and guide rail, non return mechanism can restrict the plunger displacement, avoid the plunger to stretch out too much or even deviate from, avoid the plunger to roll back the displacement too big, the inside check valve of tensioning ware suffers destruction, and the impulsive noise who produces when the followability is not good.

The hydraulic tensioner on the market at present has the following problems: 1) when the hydraulic tensioner works, the hydraulic tensioner actually belongs to a passive oil feeding state. The structure of the high-pressure oil cavity formed by passive oil feeding is limited by the pressure of a main oil duct of an engine and the opening pressure of a one-way valve to a certain extent, when the oil pressure of the main oil duct is insufficient or fluctuates greatly, the oil amount entering the tensioner is influenced, and when the oil pressure of the main oil duct is insufficient or an oil supply duct of the tensioner is blocked, the problem of failure of the tensioner can occur.

2) The fit clearance between the hydraulic tensioner plunger and the housing will determine the plunger reaction force of the tensioner when tension is established. When the fitting clearance between the plunger and the housing is too large, the tension of the chain cannot be maintained, and the vibration of the chain is restricted, so that the vibration noise thereof becomes large. When the fit clearance between the plunger and the shell is too small, the engine oil in the high-pressure oil cavity cannot be discharged in time, so that the chain tension is too large, and the service life of the chain is influenced.

3) Some hydraulic tensioners can only change the damping coefficient of the tensioner by adjusting the fit clearance between the plunger and the shell, or adopt three parts of adjusting a return spring, adjusting the fit clearance between the plunger and the shell and adjusting the length of a plunger oil drainage groove (generally located at the tail of the plunger to achieve the aim of auxiliary oil drainage) to simultaneously ensure the matching and the right of the damping coefficient of the tensioner to achieve the aim of stabilizing a timing chain system, but at the moment, a defect exists, the overpressure protection is formed by the clearance and the oil drainage area, the actual design process of the tensioner can generate interference influence, namely, the larger damping characteristic is ensured, the fit clearance between the plunger and the shell can only be reduced, but the oil drainage clearance at the moment can not form the overpressure protection enough, so that the abnormal stress of the chain system is caused. Tensioner designs can have difficulty meeting both NVH and reliability.

4) In order to ensure that the chain swing (plunger displacement) is better inhibited at the starting moment of an engine, a hydraulic tensioner generally adopts a ratchet and pawl check structure or a locking ring check structure to forcibly limit the displacement of a plunger to achieve the effect of overload protection at the starting moment, but the structures have the problems that the strokes of the pawl and the locking ring are fixed, the step distance of the plunger in the advancing and retreating processes is the width of one ratchet (the check distance is short), the plunger is equivalent to simple harmonic vibration between one step distance when being impacted by the chain, the vibration of the chain cannot be reduced to the maximum extent, but in order to ensure the durability of the ratchet, the tooth distance of the ratchet cannot be directly increased or reduced, and meanwhile, the ratchet and locking ring structure has the risks of easy abrasion or tooth breakage to cause the failure or the poor reliability of the check tensioner, therefore, the check structure of the ratchet and the locking ring has certain limitation.

Therefore, the above problems need to be solved by those skilled in the art.

Disclosure of Invention

In view of the above problems in the prior art, an object of the present invention is to provide a tensioner and an engine, which change an oil supply manner of the tensioner, avoid the chain from being subjected to a change in oil pressure, which results in an increase in chain stress and severe wear of a chain system, and increase the service life, or cause a failure of the tensioner due to an inability of a high-pressure oil chamber of the tensioner, and simultaneously, adopt an independent oil drainage mechanism and a sliding groove type automatic check device, so as to meet NVH of the tensioner, avoid additional engagement impact, and improve reliability.

In order to solve the above problem, the present invention provides a tensioner including a housing, the tensioner further including: the oil supply mechanism, the reset piece and the plunger are arranged in the shell;

the oil supply mechanism comprises a rack, a gear, an inner rotor and an outer rotor, wherein the rack is meshed with the gear, the rack is used for driving the gear to rotate, the gear is fixedly connected with the inner rotor, the inner rotor is meshed with the outer rotor, and the inner rotor is used for driving the outer rotor to rotate;

the reset piece is arranged in the plunger, the reset piece is used for pushing the plunger to reciprocate, the plunger is fixedly connected with the rack, and the plunger is used for driving the rack to move up and down.

Further, the tensioner further comprises: and the check valve is communicated with the oil outlet end of the oil supply mechanism and is used for preventing the machine oil in the high-pressure oil cavity in the oil supply mechanism from flowing back.

Further, the gear axis, the inner rotor axis and the outer rotor axis are on the same straight line.

Further, the reset piece is a spring.

Further, the tensioner further comprises a pressure relief mechanism, the oil drainage mechanism is communicated with the high-pressure oil cavity of the tensioner, and the oil drainage mechanism is used for draining redundant engine oil in the high-pressure oil cavity.

Further, the tensioner further comprises a non-return mechanism, the non-return mechanism comprises a locking plunger, a return spring and a plug, the locking plunger is used for limiting the movement of the plunger, one end of the return spring is connected with the locking plunger, the other end of the return spring is connected with the plug, and the return spring is used for pushing the locking plunger to reciprocate.

Further, the locking plunger limits movement of the plunger by catching a slide groove provided on the plunger.

Further, the length of the chute is designed according to the length of the plunger.

Further, the plunger is fixedly connected with the rack through a pin.

The invention also protects an engine, which comprises the tensioner, wherein a driving device drives the plunger of the tensioner to move through a chain.

Due to the technical scheme, the invention has the following beneficial effects:

1) according to the tensioner and the engine, the oil supply mode of the tensioner is changed, active self-supply oil supply is realized, the phenomenon that the chain is stressed to be enlarged due to overhigh pressure of engine oil is avoided, the chain system is seriously abraded, and the service lives of the chain, the guide rail and the tensioner are prolonged;

2) according to the tensioner and the engine, the oil supply mode of the tensioner is changed, active self-supply oil supply is realized, and the condition that the tensioner fails due to the fact that a high-pressure oil cavity of the tensioner cannot be established due to insufficient pressure of a main oil duct is avoided;

3) according to the tensioner and the engine, the oil drainage mechanism and the high-pressure oil cavity are mutually independent, strong interference is not generated, the counter force of the tensioner plunger is ensured not to be too large, transient change of the counter force of the tensioner caused by too much oil drainage is avoided, the tensioner plunger is enabled to follow the guide rail, and the NVH and the reliability of the tensioner are also met;

4) according to the tensioner and the engine, the sliding groove type automatic check device is adopted, and the check function is formed by the friction force between the plunger and the sliding groove and the limiting position between the sliding groove and the plunger, so that the movement process of the plunger is more stable, the additional meshing impact is avoided, and the reliability is improved.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiment or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic structural view of a tensioner provided by an embodiment of the present invention;

FIG. 2 is a schematic view of a portion of a tensioner provided by an embodiment of the present invention;

fig. 3 is a schematic view of a check mechanism of a tensioner according to an embodiment of the present invention.

In the figure, 1-shell, 2-oil supply mechanism, 21-rack, 22-gear, 23-inner rotor, 24-outer rotor, 3-reset piece, 4-plunger, 41-chute, 5-one-way valve, 6-oil drainage mechanism, 7-check mechanism, 71-locking plunger, 72-reset spring, 73-plug and 8-pin.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the invention. In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "top", "bottom", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein.

Example one

The present embodiment provides a tensioner, as shown in fig. 1, including a housing 1, further including: an oil supply mechanism 2, a reset piece 3 and a plunger 4 which are arranged in the shell 1;

the oil supply mechanism 2 comprises a rack 21, a gear 22, an inner rotor 23 and an outer rotor 24, wherein the rack 21 is meshed with the gear 22, the rack 21 is used for driving the gear 22 to rotate, the gear 22 is fixedly connected with the inner rotor 23, the inner rotor 23 is meshed with the outer rotor 24, and the inner rotor 23 is used for driving the outer rotor 24 to rotate;

reset 3 and set up in plunger 4, reset 3 is used for promoting plunger 4 reciprocating motion, plunger 4 with the fixed connection of rack 21, plunger 4 is used for driving rack 21 reciprocates.

Specifically, the tensioner further comprises: and the check valve 5 is communicated with the oil outlet end of the oil supply mechanism 2 and is used for preventing the machine oil in the high-pressure oil cavity in the oil supply mechanism 2 from flowing back.

Further, the oil inlet end and the oil outlet end of the oil supply mechanism 2 are mutually independent and closed.

Further, the axes of the gear 22, the inner rotor 23 and the outer rotor 24 are aligned.

In particular, the return member 3 is a spring.

Specifically, the plunger 4 and the rack 21 are fixedly connected through a pin 8, so that the plunger 4 and the rack 21 can be ensured to synchronously act.

Specifically, when the plunger 4 is retracted due to a force, the rack 21 is moved downward by the driving of the plunger 4, the gear 22 engaged with the rack 21 is rotated clockwise by the downward movement of the rack 21, the inner rotor 23 is rotated clockwise by the gear 22, the outer rotor 24 is also rotated clockwise at a slower speed by the engagement of the inner rotor 23 and the outer rotor 24, when the distance between the inner rotor 23 and the outer rotor 24 is relatively long, the pressure of the clearance space where the inner rotor 23 and the outer rotor 24 are engaged is lower than the pressure of the oil passage of the tensioner, the oil is pressed into the clearance space from the oil passage of the tensioner until the oil completely fills the clearance space where the inner rotor 23 and the outer rotor 24 are engaged, and as the inner rotor 23 continues to rotate under the gear 22, the inner rotor 23 with the space between the outer rotor 24 reduces gradually, exists inner rotor 23 with machine oil between the outer rotor 24 will be extruded, gets into check valve 5 with the storage space between the two of oil supply mechanism 2 machine oil in the storage space is after reaching preset pressure, and machine oil opens check valve 5 forms the high-pressure oil pocket of tensioning ware, nevertheless along with the high-pressure intracavity machine oil of tensioning ware passes through the spring promotes when plunger 4 outwards stretches out, and then drive rack 21 goes upward, rack 21 drives gear 22 anticlockwise rotation, but because the machine oil in the high-pressure oil chamber can not pass through check valve 5 flows back to oil supply mechanism 2 will continuously form the high-pressure oil pocket, forms damping system to the chain, restricts the swing of chain, wherein, the reason that the machine oil in the high-pressure oil chamber can not flow back is that the case of check valve 5 is compressed tightly at the machine oil intracavity of valve On the seat, the valve core can not move, the one-way valve 5 can not be opened, the engine oil in the high-pressure cavity can not be pressed back to the oil supply mechanism 2, the high-pressure oil cavity is continuously formed, a damping system is formed for the chain, and the swing of the chain is limited.

As shown in fig. 2, the tensioner further comprises a pressure relief mechanism 6, the oil drainage mechanism 6 is communicated with the high-pressure oil cavity of the tensioner, and the oil drainage mechanism is used for draining redundant engine oil in the high-pressure oil cavity.

Preferably, the pressure relief mechanism 6 is a pressure relief valve, when the oil pressure in the high-pressure oil chamber of the tensioner is too high, the oil pressure overcomes the spring force of the pressure relief valve, the oil drainage oil path of the valve core chain tightener of the pressure relief valve is pushed to be communicated with the high-pressure chamber, and redundant oil in the high-pressure chamber is drained to the outside of the tensioner through the oil drainage oil path to form overpressure protection, so that the abnormal abrasion of a chain system of an engine caused by the too high oil pressure in the high-pressure oil chamber is avoided, the service life of parts is reduced, and the NVH and the reliability of the tensioner.

Further, when the engine oil in the high-pressure oil cavity of the tensioner is discharged, the pressure of the engine oil in the high-pressure oil cavity of the tensioner is reduced, the valve core of the pressure release valve is pushed again under the action of the spring force, and returns to the initial position, the oil discharge oil way is stopped, the oil discharge of the tensioner is not continued, meanwhile, as the pressure of the engine oil in the high-pressure oil cavity of the tensioner is reduced, the spring is applied to the reduction of the elastic force of the plunger 4, the plunger 4 returns back to drive the oil supply mechanism 2 to move and supply oil to the high-pressure oil cavity of the tensioner again, the excessive discharged oil in the oil discharge process is compensated, dynamic balance is finally formed, the reaction force of the plunger 4 is ensured not to be too large, the transient change of the reaction force of the tensioner due to too much oil discharge is avoided, and the problem of the followability.

As shown in fig. 3, the tensioner further comprises a check mechanism 7, the check mechanism 7 comprises a locking plunger 71, a return spring 72 and a plug 73, the locking plunger 71 is used for limiting the movement of the plunger 4, the return spring 72 is connected with the locking plunger 71, the other end of the return spring 72 is connected with the plug 73, the return spring 72 is used for pushing the locking plunger 71 to reciprocate, when the plunger and the locking plunger of the tensioner are worn, the wear amount is automatically compensated through the spring under the action of the return spring force, the check failure of the tensioner is avoided, and a more reliable check effect is achieved;

specifically, the locking plunger 71 limits the movement of the plunger 4 by clamping the sliding groove 41, the sliding groove 41 is arranged on the plunger 4, the plunger of the tensioner on the shell can be always in contact with the sliding groove, the plunger movement cannot be influenced in the extension and retraction processes of the plunger of the tensioner, the plunger of the tensioner is relatively stable in the whole movement process, and compared with a pawl type or locking ring type check structure, additional engagement impact in the engagement and disengagement processes of the pawl/locking ring and the plunger in the operation process of the plunger of the tensioner is avoided.

Further, the length of the slide groove 41 is designed according to the length of the plunger 4.

The invention also protects an engine which comprises the tensioner, wherein a driving device drives the plunger 4 of the tensioner to move through a chain.

Specifically, the oil supply mechanism 2 of the tensioner comprises a rack 21, a gear 22, an inner rotor 23 and an outer rotor 24, when the engine is started, the chain swings greatly, the displacement of a plunger is also large, the stroke of the rack 21 is large, the rotation angle of the gear 22 is large, the relative oil inlet amount is large, oil cavity damping can be formed rapidly, chain vibration is buffered, and chain vibration noise is reduced.

The embodiment I provides a tensioner and an engine, which change the oil supply mode of the tensioner, realize active self-supply oil supply, avoid the chain stress from being increased due to overhigh oil pressure, avoid serious abrasion of a chain system, and improve the service lives of the chain, a guide rail and the tensioner; meanwhile, active self-supply oil supply is realized, and the problem that a tensioner fails due to the fact that a high-pressure oil cavity of the tensioner cannot be built due to insufficient pressure of a main oil duct is avoided.

The foregoing description has disclosed fully preferred embodiments of the present invention. It should be noted that those skilled in the art can make modifications to the embodiments of the present invention without departing from the scope of the appended claims. Accordingly, the scope of the appended claims is not to be limited to the specific embodiments described above.

Claims

1. A tensioner comprising a housing (1), characterized in that the tensioner further comprises: the oil supply mechanism (2), the reset piece (3) and the plunger (4) are arranged in the shell (1);

the oil supply mechanism (2) comprises a rack (21), a gear (22), an inner rotor (23) and an outer rotor (24), the rack (21) is meshed with the gear (22), the rack (21) is used for driving the gear (22) to rotate, the gear (22) is fixedly connected with the inner rotor (23), the inner rotor (23) is meshed with the outer rotor (24), and the inner rotor (23) is used for driving the outer rotor (24) to rotate;

reset piece (3) and set up in plunger (4), reset piece (3) are used for promoting plunger (4) reciprocating motion, plunger (4) with the fixed connection of rack (21), plunger (4) are used for driving rack (21) reciprocate.

2. The tensioner as in claim 1, further comprising: the check valve (5) is communicated with the oil outlet end of the oil supply mechanism (2) and is used for preventing the machine oil in the high-pressure oil cavity in the oil supply mechanism (2) from flowing back.

3. A tensioner according to claim 1, characterised in that the gear (22) axis, the inner rotor (23) axis and the outer rotor (24) axis are collinear.

4. A tensioner according to claim 1, characterised in that said return element (3) is a spring.

5. The tensioner as in claim 1, further comprising: and the oil drainage mechanism (6) is communicated with the high-pressure oil cavity of the tensioner, and the oil drainage mechanism (6) is used for draining redundant engine oil in the high-pressure oil cavity.

6. The tensioner according to claim 1, further comprising a check mechanism (7), wherein said check mechanism (7) comprises a locking plunger (71), a return spring (72) and a plug (73), said locking plunger (71) is used for limiting the movement of said plunger (4), said return spring (72) is connected with said locking plunger (71), the other end of said return spring (72) is connected with said plug (73), said return spring (72) is used for pushing said locking plunger (71) to reciprocate.

7. A tensioner according to claim 6, characterised in that said locking plunger (71) limits the movement of said plunger (4) by catching a slide groove (41), said slide groove (41) being provided on said plunger (4).

8. A tensioner according to claim 7, characterised in that the length of said slide groove (41) is designed according to the length of said plunger (4).

9. A tensioner according to claim 1, characterised in that said plunger (4) is fixedly connected to said rack (21) by means of a pin (8).

10. An engine, characterized in that the engine comprises a tensioner according to any one of claims 1-9, in which engine the drive means moves the plunger (4) of the tensioner by means of a chain.